1. Field of the Invention
The present invention relates to an electroendoscope apparatus to which a plurality of types of endoscopes having different types of solid-state imaging devices are connected.
2. Description of the Related Art
As is well known, an electroendoscope apparatus makes it possible to observe the inside of living bodies or the like which cannot be observed directly by the naked eye and is widely used for observation and curing mainly in the field of medical treatment. In recent years, electroendoscope apparatuses which convert a subject image into electrical signals by using solid-state imaging devices, such as CCDs, so as to enable the image to be observed by a monitor, have come to be widely used.
Various types of endoscopes corresponding to the places to be observed by the electroendoscope apparatus are used. These endoscopes are connected to a light source apparatus, a signal processing apparatus or the like and then used. Therefore, a plurality of types of signal processing circuits are needed to handle the types of solid-state imaging devices provided in the endoscope.
Accordingly, for the purpose of providing an apparatus which can operate a plurality of types of endoscopes having solid-state imaging devices each having a different number of pixels, an apparatus having a detection circuit of an endoscope is provided in the main body thereof has been disclosed in Japanese Patent Laid-Open No. 63-186618. This apparatus switches to the most appropriate endoscope according to the detected signals, depending upon the endoscopes to which drive pulses for the solid-state imaging device and a signal processing circuit are connected.
In addition, an electroendoscope apparatus has been disclosed in U.S. Pat. No. 4,891,695, in which features in the arrangement of pixels, such as pixel size, are made the same in two or more solid-state imaging devices of a plurality of the usable solid-state imaging devices within the apparatus. This apparatus is designed to easily switch a signal processing circuit corresponding to an endoscope having different solid-state imaging devices by using a low-cost arrangement.
However, since dedicated circuits corresponding to each of the solid-state imaging devices must be provided and switched in the conventional electroendoscope apparatus, its circuitry becomes complex and the apparatus becomes enlarged. When an endoscope having solid-state imaging devices having pixel arrangements which are quite different is used, signal processing apparatuses having different constructions need to be switched. Thus, the apparatus also becomes complex.